Midazolam acts synergistically with fentanyl for induction of anaesthesia.
The induction dose-response of midazolam was compared with the dose-response of its combination with fentanyl and with that of fentanyl alone in three groups of 60 unpremedicated, ASA physical status I or II women undergoing minor gynaecological surgery. The end-point of induction of anaesthesia was inability to open eyes upon command. Dose-response curves were determined for each group with a probit procedure and compared with an isobolographic analysis. Midazolam was found to act in synergism with fentanyl for induction of anaesthesia. Twenty-five percent of the ED50 of fentanyl was required in combination with 23% of the ED50 for midazolam to achieve the ED50 of the combination. This degree of synergism may explain mutual potentiation between opioids and benzodiazepines reported previously.
Ben-Shlomo
I
I
Department of Obstetrics and Gynaecology, Rebecca Sieff Government Hospital, Safed, Israel.
abd-el-Khalim
H
H
Ezry
J
J
Zohar
S
S
Tverskoy
M
M
D000328:Adult; D000771:Anesthesia, Intravenous; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D005283:Fentanyl / Q000494:pharmacology*; D006801:Humans; D008874:Midazolam / Q000494:pharmacology*; D008875:Middle Aged
D008874:Midazolam; D005283:Fentanyl